In addition, the Jem'Hadar are also fanatically loyal to the Founders - they see the founders as gods. This helps keep the Vorta in line, as the Jem'Hadar would rather die than allow the Vorta to act counter to the will of their gods.

The Jem'Hadar are quite important in the DS9 world, both as the muscle of the Dominion, and to show us just how the Founders feel about solids. The Founders make a show of appreciating the fealty of their minions, but also call them in to existence for their own uses and allow them to die on a whim.